From: Ramakrishnan Muthukrishnan Date: Thu, 22 Apr 2010 14:29:57 +0000 (+0530) Subject: Added pom.xml for maven compilation into a jar. X-Git-Url: https://git.rkrishnan.org/pf/content/en/?a=commitdiff_plain;h=fef797985a2c8e28f0dc7ba54f58bf37048c0dd7;p=sicp.git Added pom.xml for maven compilation into a jar. Re-arrangement of directory structure. Re-arrangement of code for compilation. --- diff --git a/pom.xml b/pom.xml new file mode 100644 index 0000000..62b756b --- /dev/null +++ b/pom.xml @@ -0,0 +1,72 @@ + + 4.0.0 + sicp + sicp + jar + 1.0-SNAPSHOT + sicp + http://maven.apache.org + Solutions to SICP in Clojure + + + + + com.theoryinpractise + clojure-maven-plugin + 1.3.2 + + + compile-clojure + compile + + compile + + + + + + src/main/clojure + + + + + + + + + org.clojure + clojure + 1.1.0 + + + org.clojure + clojure-contrib + 1.1.0 + + + + + + clojure-snapshots + http://build.clojure.org/snapshots + + false + + + true + + + + clojure-releases + http://build.clojure.org/releases + + true + + + false + + + + + diff --git a/src/main/clojure/sicp/ch1_1.clj b/src/main/clojure/sicp/ch1_1.clj index 783e139..34856cd 100644 --- a/src/main/clojure/sicp/ch1_1.clj +++ b/src/main/clojure/sicp/ch1_1.clj @@ -1,4 +1,4 @@ -(ns sicp.chapter1.ch1_1) +(ns sicp.ch1-1) (defn square [x] (* x x)) diff --git a/src/main/clojure/sicp/ch1_2.clj b/src/main/clojure/sicp/ch1_2.clj index 13b99d1..18c14bd 100644 --- a/src/main/clojure/sicp/ch1_2.clj +++ b/src/main/clojure/sicp/ch1_2.clj @@ -1,4 +1,4 @@ -(ns sicp.chapter1.ch1_2 +(ns sicp.ch1-2 (:use (clojure.contrib trace math))) @@ -18,40 +18,40 @@ (defn factorial3 [n] (reduce * (range 1 (inc n)))) -(comment - user> (dotrace [factorial] (factorial 3)) - TRACE t2701: (factorial 3) - TRACE t2702: | (factorial 2) - TRACE t2703: | | (factorial 1) - TRACE t2703: | | => 1 - TRACE t2702: | => 2 - TRACE t2701: => 6 - 6 -) - -(comment - sicp.chapter1.ch1_2> (dotrace [factorial] (factorial 6)) - TRACE t2778: (factorial 6) - TRACE t2779: | (factorial 5) - TRACE t2780: | | (factorial 4) - TRACE t2781: | | | (factorial 3) - TRACE t2782: | | | | (factorial 2) - TRACE t2783: | | | | | (factorial 1) - TRACE t2783: | | | | | => 1 - TRACE t2782: | | | | => 2 - TRACE t2781: | | | => 6 - TRACE t2780: | | => 24 - TRACE t2779: | => 120 - TRACE t2778: => 720 - 720 - ) - -(comment - sicp.chapter1.ch1_2> (dotrace [factorial2] (factorial2 6)) - TRACE t2806: (factorial2 6) - TRACE t2806: => 720 - 720 - ) +;; (comment +;; user> (dotrace [factorial] (factorial 3)) +;; TRACE t2701: (factorial 3) +;; TRACE t2702: | (factorial 2) +;; TRACE t2703: | | (factorial 1) +;; TRACE t2703: | | => 1 +;; TRACE t2702: | => 2 +;; TRACE t2701: => 6 +;; 6 +;; ) + +;; (comment +;; sicp.chapter1.ch1_2> (dotrace [factorial] (factorial 6)) +;; TRACE t2778: (factorial 6) +;; TRACE t2779: | (factorial 5) +;; TRACE t2780: | | (factorial 4) +;; TRACE t2781: | | | (factorial 3) +;; TRACE t2782: | | | | (factorial 2) +;; TRACE t2783: | | | | | (factorial 1) +;; TRACE t2783: | | | | | => 1 +;; TRACE t2782: | | | | => 2 +;; TRACE t2781: | | | => 6 +;; TRACE t2780: | | => 24 +;; TRACE t2779: | => 120 +;; TRACE t2778: => 720 +;; 720 +;; ) + +;; (comment +;; sicp.chapter1.ch1_2> (dotrace [factorial2] (factorial2 6)) +;; TRACE t2806: (factorial2 6) +;; TRACE t2806: => 720 +;; 720 +;; ) (defn fact-iter [product counter max-count] (if (> counter max-count) @@ -63,26 +63,26 @@ (defn factorial [n] (fact-iter 1 1 n)) -(comment -user> (dotrace [factorial fact-iter] (factorial 6)) -TRACE t2378: (factorial 6) -TRACE t2379: | (fact-iter 1 1 6) -TRACE t2380: | | (fact-iter 1 2 6) -TRACE t2381: | | | (fact-iter 2 3 6) -TRACE t2382: | | | | (fact-iter 6 4 6) -TRACE t2383: | | | | | (fact-iter 24 5 6) -TRACE t2384: | | | | | | (fact-iter 120 6 6) -TRACE t2385: | | | | | | | (fact-iter 720 7 6) -TRACE t2385: | | | | | | | => 720 -TRACE t2384: | | | | | | => 720 -TRACE t2383: | | | | | => 720 -TRACE t2382: | | | | => 720 -TRACE t2381: | | | => 720 -TRACE t2380: | | => 720 -TRACE t2379: | => 720 -TRACE t2378: => 720 -720 -) +;; (comment +;; user> (dotrace [factorial fact-iter] (factorial 6)) +;; TRACE t2378: (factorial 6) +;; TRACE t2379: | (fact-iter 1 1 6) +;; TRACE t2380: | | (fact-iter 1 2 6) +;; TRACE t2381: | | | (fact-iter 2 3 6) +;; TRACE t2382: | | | | (fact-iter 6 4 6) +;; TRACE t2383: | | | | | (fact-iter 24 5 6) +;; TRACE t2384: | | | | | | (fact-iter 120 6 6) +;; TRACE t2385: | | | | | | | (fact-iter 720 7 6) +;; TRACE t2385: | | | | | | | => 720 +;; TRACE t2384: | | | | | | => 720 +;; TRACE t2383: | | | | | => 720 +;; TRACE t2382: | | | | => 720 +;; TRACE t2381: | | | => 720 +;; TRACE t2380: | | => 720 +;; TRACE t2379: | => 720 +;; TRACE t2378: => 720 +;; 720 +;; ) ;; observation: clojure loop-recur construct is essentially the same as ;; the iterative version. @@ -93,43 +93,44 @@ TRACE t2378: => 720 b (inc (++ (dec a) b)))) -(comment - This version is a recursive process, where the previous call increments - the sum by 1 and each call decrement the first operand by 1. +;; (comment +;; This version is a recursive process, where the previous call increments +;; the sum by 1 and each call decrement the first operand by 1. -user> (dotrace [++] (++ 4 5)) -TRACE t3745: (++ 4 5) -TRACE t3746: | (++ 3 5) -TRACE t3747: | | (++ 2 5) -TRACE t3748: | | | (++ 1 5) -TRACE t3749: | | | | (++ 0 5) -TRACE t3749: | | | | => 5 -TRACE t3748: | | | => 6 -TRACE t3747: | | => 7 -TRACE t3746: | => 8 -TRACE t3745: => 9 -9 -) +;; user> (dotrace [++] (++ 4 5)) +;; TRACE t3745: (++ 4 5) +;; TRACE t3746: | (++ 3 5) +;; TRACE t3747: | | (++ 2 5) +;; TRACE t3748: | | | (++ 1 5) +;; TRACE t3749: | | | | (++ 0 5) +;; TRACE t3749: | | | | => 5 +;; TRACE t3748: | | | => 6 +;; TRACE t3747: | | => 7 +;; TRACE t3746: | => 8 +;; TRACE t3745: => 9 +;; 9 +;; ) + (defn ++ [a b] (if (= a 0) b (++ (dec a) (inc b)))) -(comment +;; (comment -user> (dotrace [++] (++ 4 5)) -TRACE t3766: (++ 4 5) -TRACE t3767: | (++ 3 6) -TRACE t3768: | | (++ 2 7) -TRACE t3769: | | | (++ 1 8) -TRACE t3770: | | | | (++ 0 9) -TRACE t3770: | | | | => 9 -TRACE t3769: | | | => 9 -TRACE t3768: | | => 9 -TRACE t3767: | => 9 -TRACE t3766: => 9 -9 -) +;; user> (dotrace [++] (++ 4 5)) +;; TRACE t3766: (++ 4 5) +;; TRACE t3767: | (++ 3 6) +;; TRACE t3768: | | (++ 2 7) +;; TRACE t3769: | | | (++ 1 8) +;; TRACE t3770: | | | | (++ 0 9) +;; TRACE t3770: | | | | => 9 +;; TRACE t3769: | | | => 9 +;; TRACE t3768: | | => 9 +;; TRACE t3767: | => 9 +;; TRACE t3766: => 9 +;; 9 +;; ) ;; exercise 1.10 ;; ackerman functions @@ -151,16 +152,16 @@ user> (A 3 3) (defn f [n] (A 0 n)) ; f(n) = 2n (defn g [n] (A 1 n)) ; g(n) = 2^n -(comment - g (n) = A (1,n) - = A (0, A (1, n-1)) = f (A(1,n-1)) - = f (f (1,n-2)) - ..... - = f (f (f ... f (1,(n- (n-1))))) - = f (f (f ... 2)) - = 2 * (2^(n-1)) - = 2^n -) +;; (comment +;; g (n) = A (1,n) +;; = A (0, A (1, n-1)) = f (A(1,n-1)) +;; = f (f (1,n-2)) +;; ..... +;; = f (f (f ... f (1,(n- (n-1))))) +;; = f (f (f ... 2)) +;; = 2 * (2^(n-1)) +;; = 2^n +;; ) (defn h [n] (A 2 n)) ; h(n) = 2^(n^2) @@ -172,26 +173,15 @@ user> (A 3 3) (fib (- n 2))))) ;; iterative version -(defn fib [n] - (fib-iter 1 0 n)) - (defn fib-iter [a b count] (if (= count 0) b (fib-iter (+ a b) a (dec count)))) -;; example: counting changes -(defn count-change [amount] - (cc amount 5)) - -(defn cc [amount kinds-of-coins] - (cond (= amount 0) 1 - (or (< amount 0) (= kinds-of-coins 0)) 0 - :else (+ (cc amount (- kinds-of-coins 1)) - (cc (- amount - (first-denomination kinds-of-coins)) - kinds-of-coins)))) +(defn fib [n] + (fib-iter 1 0 n)) +;; example: counting changes (defn first-denomination [kinds-of-coins] (cond (= kinds-of-coins 1) 1 (= kinds-of-coins 2) 5 @@ -199,9 +189,21 @@ user> (A 3 3) (= kinds-of-coins 4) 25 (= kinds-of-coins 5) 50)) + (defn first-denomination [kinds-of-coins] ({1 1 2 5 3 10 4 25 5 50} kinds-of-coins)) +(defn cc [amount kinds-of-coins] + (cond (= amount 0) 1 + (or (< amount 0) (= kinds-of-coins 0)) 0 + :else (+ (cc amount (- kinds-of-coins 1)) + (cc (- amount + (first-denomination kinds-of-coins)) + kinds-of-coins)))) + +(defn count-change [amount] + (cc amount 5)) + ;; exercise 1.11: A function f is defined by the rule that f(n) = n if n < 3 ;; and f(n) = f(n - 1) + 2f(n - 2) + 3f(n - 3) if n> 3. ;; Write a procedure that computes f by means of a recursive @@ -220,11 +222,6 @@ user> (map f (range 10)) ) ;; ex 1.11: iterative version -(defn f [n] - (if (< n 3) - n - (f-iter n 2 1 0))) - (defn f-iter [count prev0 prev1 prev2] (if (= count 3) (+ prev0 @@ -237,6 +234,11 @@ user> (map f (range 10)) prev0 prev1))) +(defn f [n] + (if (< n 3) + n + (f-iter n 2 1 0))) + ;; ex 1.11: iterative version with let (defn f-iter [count prev0 prev1 prev2] (let [res (+ prev0 (* 2 prev1) (* 3 prev2))] @@ -276,10 +278,10 @@ See the pdfs in the directory for the answers. (let [phi (/ (+ 1 (sqrt 5)) 2)] (/ (expt phi n) (sqrt 5)))) -(comment -user> (map fib-approx (range 10)) -(0.4472135954999579 0.7236067977499789 1.1708203932499368 1.8944271909999157 3.065247584249853 4.959674775249769 8.024922359499623 12.984597134749393 21.009519494249016 33.99411662899841) -) +;; (comment +;; user> (map fib-approx (range 10)) +;; (0.4472135954999579 0.7236067977499789 1.1708203932499368 1.8944271909999157 3.065247584249853 4.959674775249769 8.024922359499623 12.984597134749393 21.009519494249016 33.99411662899841) +;; ) ;; exercise 1.14: tree of (count-changes 11) (comment @@ -289,126 +291,127 @@ user> (map fib-approx (range 10)) ;; order of size and computation ;; see PDF, but below is the trace tree. -(comment -user> (use 'clojure.contrib.trace) -nil -user> (dotrace [count-change cc] (count-change 11)) -TRACE t2609: (count-change 11) -TRACE t2610: | (cc 11 5) -TRACE t2611: | | (cc 11 4) -TRACE t2612: | | | (cc 11 3) -TRACE t2613: | | | | (cc 11 2) -TRACE t2614: | | | | | (cc 11 1) -TRACE t2615: | | | | | | (cc 11 0) -TRACE t2615: | | | | | | => 0 -TRACE t2616: | | | | | | (cc 10 1) -TRACE t2617: | | | | | | | (cc 10 0) -TRACE t2617: | | | | | | | => 0 -TRACE t2618: | | | | | | | (cc 9 1) -TRACE t2619: | | | | | | | | (cc 9 0) -TRACE t2619: | | | | | | | | => 0 -TRACE t2620: | | | | | | | | (cc 8 1) -TRACE t2621: | | | | | | | | | (cc 8 0) -TRACE t2621: | | | | | | | | | => 0 -TRACE t2622: | | | | | | | | | (cc 7 1) -TRACE t2623: | | | | | | | | | | (cc 7 0) -TRACE t2623: | | | | | | | | | | => 0 -TRACE t2624: | | | | | | | | | | (cc 6 1) -TRACE t2625: | | | | | | | | | | | (cc 6 0) -TRACE t2625: | | | | | | | | | | | => 0 -TRACE t2626: | | | | | | | | | | | (cc 5 1) -TRACE t2627: | | | | | | | | | | | | (cc 5 0) -TRACE t2627: | | | | | | | | | | | | => 0 -TRACE t2628: | | | | | | | | | | | | (cc 4 1) -TRACE t2629: | | | | | | | | | | | | | (cc 4 0) -TRACE t2629: | | | | | | | | | | | | | => 0 -TRACE t2630: | | | | | | | | | | | | | (cc 3 1) -TRACE t2631: | | | | | | | | | | | | | | (cc 3 0) -TRACE t2631: | | | | | | | | | | | | | | => 0 -TRACE t2632: | | | | | | | | | | | | | | (cc 2 1) -TRACE t2633: | | | | | | | | | | | | | | | (cc 2 0) -TRACE t2633: | | | | | | | | | | | | | | | => 0 -TRACE t2634: | | | | | | | | | | | | | | | (cc 1 1) -TRACE t2635: | | | | | | | | | | | | | | | | (cc 1 0) -TRACE t2635: | | | | | | | | | | | | | | | | => 0 -TRACE t2636: | | | | | | | | | | | | | | | | (cc 0 1) -TRACE t2636: | | | | | | | | | | | | | | | | => 1 -TRACE t2634: | | | | | | | | | | | | | | | => 1 -TRACE t2632: | | | | | | | | | | | | | | => 1 -TRACE t2630: | | | | | | | | | | | | | => 1 -TRACE t2628: | | | | | | | | | | | | => 1 -TRACE t2626: | | | | | | | | | | | => 1 -TRACE t2624: | | | | | | | | | | => 1 -TRACE t2622: | | | | | | | | | => 1 -TRACE t2620: | | | | | | | | => 1 -TRACE t2618: | | | | | | | => 1 -TRACE t2616: | | | | | | => 1 -TRACE t2614: | | | | | => 1 -TRACE t2637: | | | | | (cc 6 2) -TRACE t2638: | | | | | | (cc 6 1) -TRACE t2639: | | | | | | | (cc 6 0) -TRACE t2639: | | | | | | | => 0 -TRACE t2640: | | | | | | | (cc 5 1) -TRACE t2641: | | | | | | | | (cc 5 0) -TRACE t2641: | | | | | | | | => 0 -TRACE t2642: | | | | | | | | (cc 4 1) -TRACE t2643: | | | | | | | | | (cc 4 0) -TRACE t2643: | | | | | | | | | => 0 -TRACE t2644: | | | | | | | | | (cc 3 1) -TRACE t2645: | | | | | | | | | | (cc 3 0) -TRACE t2645: | | | | | | | | | | => 0 -TRACE t2646: | | | | | | | | | | (cc 2 1) -TRACE t2647: | | | | | | | | | | | (cc 2 0) -TRACE t2647: | | | | | | | | | | | => 0 -TRACE t2648: | | | | | | | | | | | (cc 1 1) -TRACE t2649: | | | | | | | | | | | | (cc 1 0) -TRACE t2649: | | | | | | | | | | | | => 0 -TRACE t2650: | | | | | | | | | | | | (cc 0 1) -TRACE t2650: | | | | | | | | | | | | => 1 -TRACE t2648: | | | | | | | | | | | => 1 -TRACE t2646: | | | | | | | | | | => 1 -TRACE t2644: | | | | | | | | | => 1 -TRACE t2642: | | | | | | | | => 1 -TRACE t2640: | | | | | | | => 1 -TRACE t2638: | | | | | | => 1 -TRACE t2651: | | | | | | (cc 1 2) -TRACE t2652: | | | | | | | (cc 1 1) -TRACE t2653: | | | | | | | | (cc 1 0) -TRACE t2653: | | | | | | | | => 0 -TRACE t2654: | | | | | | | | (cc 0 1) -TRACE t2654: | | | | | | | | => 1 -TRACE t2652: | | | | | | | => 1 -TRACE t2655: | | | | | | | (cc -4 2) -TRACE t2655: | | | | | | | => 0 -TRACE t2651: | | | | | | => 1 -TRACE t2637: | | | | | => 2 -TRACE t2613: | | | | => 3 -TRACE t2656: | | | | (cc 1 3) -TRACE t2657: | | | | | (cc 1 2) -TRACE t2658: | | | | | | (cc 1 1) -TRACE t2659: | | | | | | | (cc 1 0) -TRACE t2659: | | | | | | | => 0 -TRACE t2660: | | | | | | | (cc 0 1) -TRACE t2660: | | | | | | | => 1 -TRACE t2658: | | | | | | => 1 -TRACE t2661: | | | | | | (cc -4 2) -TRACE t2661: | | | | | | => 0 -TRACE t2657: | | | | | => 1 -TRACE t2662: | | | | | (cc -9 3) -TRACE t2662: | | | | | => 0 -TRACE t2656: | | | | => 1 -TRACE t2612: | | | => 4 -TRACE t2663: | | | (cc -14 4) -TRACE t2663: | | | => 0 -TRACE t2611: | | => 4 -TRACE t2664: | | (cc -39 5) -TRACE t2664: | | => 0 -TRACE t2610: | => 4 -TRACE t2609: => 4 -4 -) -;; TODO: orders of growth in space and number of steps. +;; (comment +;; user> (use 'clojure.contrib.trace) +;; nil +;; user> (dotrace [count-change cc] (count-change 11)) +;; TRACE t2609: (count-change 11) +;; TRACE t2610: | (cc 11 5) +;; TRACE t2611: | | (cc 11 4) +;; TRACE t2612: | | | (cc 11 3) +;; TRACE t2613: | | | | (cc 11 2) +;; TRACE t2614: | | | | | (cc 11 1) +;; TRACE t2615: | | | | | | (cc 11 0) +;; TRACE t2615: | | | | | | => 0 +;; TRACE t2616: | | | | | | (cc 10 1) +;; TRACE t2617: | | | | | | | (cc 10 0) +;; TRACE t2617: | | | | | | | => 0 +;; TRACE t2618: | | | | | | | (cc 9 1) +;; TRACE t2619: | | | | | | | | (cc 9 0) +;; TRACE t2619: | | | | | | | | => 0 +;; TRACE t2620: | | | | | | | | (cc 8 1) +;; TRACE t2621: | | | | | | | | | (cc 8 0) +;; TRACE t2621: | | | | | | | | | => 0 +;; TRACE t2622: | | | | | | | | | (cc 7 1) +;; TRACE t2623: | | | | | | | | | | (cc 7 0) +;; TRACE t2623: | | | | | | | | | | => 0 +;; TRACE t2624: | | | | | | | | | | (cc 6 1) +;; TRACE t2625: | | | | | | | | | | | (cc 6 0) +;; TRACE t2625: | | | | | | | | | | | => 0 +;; TRACE t2626: | | | | | | | | | | | (cc 5 1) +;; TRACE t2627: | | | | | | | | | | | | (cc 5 0) +;; TRACE t2627: | | | | | | | | | | | | => 0 +;; TRACE t2628: | | | | | | | | | | | | (cc 4 1) +;; TRACE t2629: | | | | | | | | | | | | | (cc 4 0) +;; TRACE t2629: | | | | | | | | | | | | | => 0 +;; TRACE t2630: | | | | | | | | | | | | | (cc 3 1) +;; TRACE t2631: | | | | | | | | | | | | | | (cc 3 0) +;; TRACE t2631: | | | | | | | | | | | | | | => 0 +;; TRACE t2632: | | | | | | | | | | | | | | (cc 2 1) +;; TRACE t2633: | | | | | | | | | | | | | | | (cc 2 0) +;; TRACE t2633: | | | | | | | | | | | | | | | => 0 +;; TRACE t2634: | | | | | | | | | | | | | | | (cc 1 1) +;; TRACE t2635: | | | | | | | | | | | | | | | | (cc 1 0) +;; TRACE t2635: | | | | | | | | | | | | | | | | => 0 +;; TRACE t2636: | | | | | | | | | | | | | | | | (cc 0 1) +;; TRACE t2636: | | | | | | | | | | | | | | | | => 1 +;; TRACE t2634: | | | | | | | | | | | | | | | => 1 +;; TRACE t2632: | | | | | | | | | | | | | | => 1 +;; TRACE t2630: | | | | | | | | | | | | | => 1 +;; TRACE t2628: | | | | | | | | | | | | => 1 +;; TRACE t2626: | | | | | | | | | | | => 1 +;; TRACE t2624: | | | | | | | | | | => 1 +;; TRACE t2622: | | | | | | | | | => 1 +;; TRACE t2620: | | | | | | | | => 1 +;; TRACE t2618: | | | | | | | => 1 +;; TRACE t2616: | | | | | | => 1 +;; TRACE t2614: | | | | | => 1 +;; TRACE t2637: | | | | | (cc 6 2) +;; TRACE t2638: | | | | | | (cc 6 1) +;; TRACE t2639: | | | | | | | (cc 6 0) +;; TRACE t2639: | | | | | | | => 0 +;; TRACE t2640: | | | | | | | (cc 5 1) +;; TRACE t2641: | | | | | | | | (cc 5 0) +;; TRACE t2641: | | | | | | | | => 0 +;; TRACE t2642: | | | | | | | | (cc 4 1) +;; TRACE t2643: | | | | | | | | | (cc 4 0) +;; TRACE t2643: | | | | | | | | | => 0 +;; TRACE t2644: | | | | | | | | | (cc 3 1) +;; TRACE t2645: | | | | | | | | | | (cc 3 0) +;; TRACE t2645: | | | | | | | | | | => 0 +;; TRACE t2646: | | | | | | | | | | (cc 2 1) +;; TRACE t2647: | | | | | | | | | | | (cc 2 0) +;; TRACE t2647: | | | | | | | | | | | => 0 +;; TRACE t2648: | | | | | | | | | | | (cc 1 1) +;; TRACE t2649: | | | | | | | | | | | | (cc 1 0) +;; TRACE t2649: | | | | | | | | | | | | => 0 +;; TRACE t2650: | | | | | | | | | | | | (cc 0 1) +;; TRACE t2650: | | | | | | | | | | | | => 1 +;; TRACE t2648: | | | | | | | | | | | => 1 +;; TRACE t2646: | | | | | | | | | | => 1 +;; TRACE t2644: | | | | | | | | | => 1 +;; TRACE t2642: | | | | | | | | => 1 +;; TRACE t2640: | | | | | | | => 1 +;; TRACE t2638: | | | | | | => 1 +;; TRACE t2651: | | | | | | (cc 1 2) +;; TRACE t2652: | | | | | | | (cc 1 1) +;; TRACE t2653: | | | | | | | | (cc 1 0) +;; TRACE t2653: | | | | | | | | => 0 +;; TRACE t2654: | | | | | | | | (cc 0 1) +;; TRACE t2654: | | | | | | | | => 1 +;; TRACE t2652: | | | | | | | => 1 +;; TRACE t2655: | | | | | | | (cc -4 2) +;; TRACE t2655: | | | | | | | => 0 +;; TRACE t2651: | | | | | | => 1 +;; TRACE t2637: | | | | | => 2 +;; TRACE t2613: | | | | => 3 +;; TRACE t2656: | | | | (cc 1 3) +;; TRACE t2657: | | | | | (cc 1 2) +;; TRACE t2658: | | | | | | (cc 1 1) +;; TRACE t2659: | | | | | | | (cc 1 0) +;; TRACE t2659: | | | | | | | => 0 +;; TRACE t2660: | | | | | | | (cc 0 1) +;; TRACE t2660: | | | | | | | => 1 +;; TRACE t2658: | | | | | | => 1 +;; TRACE t2661: | | | | | | (cc -4 2) +;; TRACE t2661: | | | | | | => 0 +;; TRACE t2657: | | | | | => 1 +;; TRACE t2662: | | | | | (cc -9 3) +;; TRACE t2662: | | | | | => 0 +;; TRACE t2656: | | | | => 1 +;; TRACE t2612: | | | => 4 +;; TRACE t2663: | | | (cc -14 4) +;; TRACE t2663: | | | => 0 +;; TRACE t2611: | | => 4 +;; TRACE t2664: | | (cc -39 5) +;; TRACE t2664: | | => 0 +;; TRACE t2610: | => 4 +;; TRACE t2609: => 4 +;; 4 +;; ) + +;; TODO: orders of growth in space and number of steps. ;; exercise 1.15: sin (x) calculation ;; a. How many times is the procedure p applied when (sine 12.15) @@ -426,20 +429,20 @@ TRACE t2609: => 4 (p (sine (/ angle 3.0))))) ;; solution to (a) => 5 -(comment -user> (dotrace [p] (sine 12.15)) -TRACE t2490: (p 0.049999999999999996) -TRACE t2490: => 0.1495 -TRACE t2491: (p 0.1495) -TRACE t2491: => 0.4351345505 -TRACE t2492: (p 0.4351345505) -TRACE t2492: => 0.9758465331678772 -TRACE t2493: (p 0.9758465331678772) -TRACE t2493: => -0.7895631144708228 -TRACE t2494: (p -0.7895631144708228) -TRACE t2494: => -0.39980345741334 --0.39980345741334 -) +;; (comment +;; user> (dotrace [p] (sine 12.15)) +;; TRACE t2490: (p 0.049999999999999996) +;; TRACE t2490: => 0.1495 +;; TRACE t2491: (p 0.1495) +;; TRACE t2491: => 0.4351345505 +;; TRACE t2492: (p 0.4351345505) +;; TRACE t2492: => 0.9758465331678772 +;; TRACE t2493: (p 0.9758465331678772) +;; TRACE t2493: => -0.7895631144708228 +;; TRACE t2494: (p -0.7895631144708228) +;; TRACE t2494: => -0.39980345741334 +;; -0.39980345741334 +;; ) ;; solution to b ;; both space and number of steps grows as log3(a) -> log a to the base 3. @@ -454,36 +457,34 @@ TRACE t2494: => -0.39980345741334 ;; 1.2.4: exponentiation ;; computing b^n -(defn expt [b n] - (if (= n 0) - 1 - (* b (expt b (dec n))))) ;; iterative -(defn expt [b n] - (expt-iter b n 1)) - (defn expt-iter [base counter product] (if (= counter 0) product - (expt-iter b + (expt-iter base (dec counter) (* product base)))) +(defn myexpt [b n] + (expt-iter b n 1)) + +(defn myexpt [b n] + (if (= n 0) + 1 + (* b (myexpt b (dec n))))) + ;; fast version +(defn square [x] + (* x x)) + (defn fast-expt [b n] (cond (= n 0) 1 (even? n) (square (fast-expt b (/ n 2))) :else (* b (fast-expt b (dec n))))) -(defn even? [x] - (= (rem x 2) 0)) - -(defn square [x] - (* x x)) - ;; exercise 1.16: -(defn expt [b n] +(defn myexpt [b n] (expt-iter b n 1)) (defn expt-iter [b n a] @@ -497,6 +498,13 @@ TRACE t2494: => -0.39980345741334 0 (+ a (mult a (- b 1))))) +;; double +(defn twice [x] + (* 2 x)) + +(defn half [x] + (/ x 2)) + ;; product = 2 * (a * (b/2)) for even b ;; = a + (a * (b - 1)) for odd b (defn fast-mult [a b] @@ -505,43 +513,33 @@ TRACE t2494: => -0.39980345741334 (even? b) (twice (fast-mult a (half b))) :else (+ a (fast-mult a (- b 1))))) -;; double -(defn twice [x] - (* 2 x)) - -(defn half [x] - (/ x 2)) - ;; exercise 1.18: iterative multiply thru addition ;; the idea is to keep a state variable. -(defn fast-mult-new [a b] - (fast-mult-iter a b 0)) - (defn fast-mult-iter [a b k] (cond (= b 0) k (even? b) (fast-mult-iter (twice a) (half b) k) :else (fast-mult-iter a (- b 1) (+ k a)))) -(comment -user> (dotrace [fast-mult-new fast-mult-iter] (fast-mult-new 2 3)) -TRACE t2915: (fast-mult-new 2 3) -TRACE t2916: | (fast-mult-iter 2 3 0) -TRACE t2917: | | (fast-mult-iter 2 2 2) -TRACE t2918: | | | (fast-mult-iter 4 1 2) -TRACE t2919: | | | | (fast-mult-iter 4 0 6) -TRACE t2919: | | | | => 6 -TRACE t2918: | | | => 6 -TRACE t2917: | | => 6 -TRACE t2916: | => 6 -TRACE t2915: => 6 -6 -) +(defn fast-mult-new [a b] + (fast-mult-iter a b 0)) + +;; (comment +;; user> (dotrace [fast-mult-new fast-mult-iter] (fast-mult-new 2 3)) +;; TRACE t2915: (fast-mult-new 2 3) +;; TRACE t2916: | (fast-mult-iter 2 3 0) +;; TRACE t2917: | | (fast-mult-iter 2 2 2) +;; TRACE t2918: | | | (fast-mult-iter 4 1 2) +;; TRACE t2919: | | | | (fast-mult-iter 4 0 6) +;; TRACE t2919: | | | | => 6 +;; TRACE t2918: | | | => 6 +;; TRACE t2917: | | => 6 +;; TRACE t2916: | => 6 +;; TRACE t2915: => 6 +;; 6 +;; ) ;; exercise 1.19: fast fibonacci ;; see the pdf of the notebook scan for the derivation of p' and q' -(defn ffib [n] - (ffib-iter 1 0 0 1 n)) - (defn ffib-iter [a b p q count] (cond (= count 0) b (even? count) @@ -555,3 +553,7 @@ TRACE t2915: => 6 p q (- count 1)))) + +(defn ffib [n] + (ffib-iter 1 0 0 1 n)) + diff --git a/src/main/clojure/sicp/misc/argue.clj b/src/main/clojure/sicp/misc/argue.clj deleted file mode 100644 index f423b2f..0000000 --- a/src/main/clojure/sicp/misc/argue.clj +++ /dev/null @@ -1,12 +0,0 @@ -(ns sicp-clj) - -(defn argue [sentence] - (when-not (empty? sentence) - (concat (opposite (first sentence)) (argue (rest sentence))))) - -(defn opposite [word] - (cond (= word "like") "hate" - (= word "hate") "like" - (= word "wonderful") "terrible" - (= word "terrible") "wonderful" - :else word)) \ No newline at end of file diff --git a/src/main/clojure/sicp/misc/plural.clj b/src/main/clojure/sicp/misc/plural.clj deleted file mode 100644 index 6ded4e0..0000000 --- a/src/main/clojure/sicp/misc/plural.clj +++ /dev/null @@ -1,5 +0,0 @@ -;; from Brian Harvey's Spring 2008 lecture 01. -(defn plural [wd] - (if (= (last wd) \y) - (apply str (concat (butlast wd) "ies")) - (apply str (concat wd "s")))) \ No newline at end of file